Sheet material joint



July 4, 1939. E, L B R ET 2,164,634

SHEET MATERIAL JOINT Filed May 21, 1938 m2. Edward]; fiery/22% (flrrogrysy s Patented July 4, 1939 UNITED STATES PATENT GFFICE SHEET MATERIAL JOINT Application May 21, 1938, Serial No. 209,251

3 Claims.

The invention relates to articles made of sheet material and more particularly to an improved construction for securing together or joining portions of such material.

The general objects of the present invention are to provide a joint structure capable of securing together portions of sheet material without rupturing or straining adjacent parts of the material, which may be easily and cheaply formed, and which may be quickly and readily disengaged and reengaged without harming the sheet material.

Further objects and advantages of the invention will become apparent as the following description proceeds taken in connection with the accompanying drawing in which:

Figure 1 is a perspective View of a sheet metal container made up of several sheets of metal secured together by joints embodying the present invention;

Fig. 2 is an enlarged fragmentary detail View of one of the joints included in the device of Fig. 1;

Fig. 3 is an enlarged exploded perspective view of the parts of the joint prior to its completion;

Fig. 4 is a transverse sectional view along the line 4-4 in Fig. 2;

Fig. 5 is a transverse sectional view similar to Fig. 4 of the same type of joint applied to sheets of dissimilar materials;

Fig. 6 is a partial perspective view of a tool adapted for use in forming the sheet material joints herein disclosed.

For purposes of illustration of its various novel features, the invention has been shown herein as applied to the construction of a box or casing such as is used as the housing for a radio receiver tuner although the type of sheet material joint herein disclosed is applicable to a large variety of other structures and is by no means to be taken as limited to this particular embodiment.

The casing structure of Fig. 1 is made up of a plurality of sheets of metal preferably fashioned as stampings and including end plates iii, a top plate II, a front plate l2 and an interiorly located same. A part of the outer edge or end portion of the lug is separated from the remainder thereof along a line of cleavage substantially coincident with the plane of the top of the surface of the second or slotted sheet of material but lying 5 slightly beyond the same so that this edge portion of the lug can be displaced out of the plane of the remainder of the lug to overlie the second sheet without distorting the remainder of either of the sheets of material. 10

In the preferred construction illustrated, an elongated generally rectangular aperture or window I6 is formed in the lug l4 and the height of this aperture is substantially equal to the thickness of the second sheet of material i I. The line 15 of cleavage between the central edge portion of the lug and the remainder thereof thus lies sub stantially in the plane of the surface of the second sheet H. Consequently, when the lug I4 is inserted into the slot l5, the central part of the 2f edge portion of the lug 14 can be distorted laterally out of the plane of the remainder of the lug in the form of a rib i'! to overlie the adjacent space of the sheet N. This rib is arranged at right angles to the face of the sheet H and 25 abuts against the same thus firmly holding the sheets I! and 42 in assembled relation (Figs. 2 and 4). The lugs and complemental slots for the joints may be advantageously formed in the same stamping or punching operations in which the 30 sheets are formed.

A simple tool may be provided for distorting the lugs into the ribbed form described. The tool may, for example, be made in the form of a pair of pliers I8 (Fig. 6) having a rib l9 on one jaw 35 and a complemental groove 20 on the opposing jaw. These jaws form dies for distorting the lug to the shape desired by simply pinching the outer end of the lug which extends beyond the surface of the sheet of material. The flat surfaces of the plier jaws on each side of the rib l9 grip the ends of the lug so that there is no strain or pull exerted on the portion of the sheet at the root of the lug.

Despite its permanency and strength, the joint 45 described can readily be disengaged by flattening out the lug M to its original shape and then withdrawing it from the slot l5. For this purpose a pair of ordinary flat jawed pliers may be utilized to pinch the bent lug back to its original 50 flat shape. It has been found that lugs of this type can be bent into and out of their distorted or ribbed shape a large number of times Without straining, twisting or in any way injuring the associated parts of sheet material.

Lug joints of the type described are particularly useful in securing sheets of metal such as the sheet I? (Fig. to sheets of more frangible and brittle material such as a sheet of Bakelite Il In such case, the lug M is formed in the metal sheet and the slot 15 fashioned in the Bakelite sheet. When the portion I I of the lu I4 is bent in the form of a rib to abut against and overlie the surface of the sheet H there is no force exerted on the latter which would tend to crack or break it. As to the latter point, it will be noted that the window or aperture H5 in the plate [2 registers with the adjacent edge of the sheet ll so that this edge remains free of any strains or the like.

Although a particular embodiment of the in vention has been shown and described in some detail for purposes of illustration of its various novel features, there is no intention to limit the invention to such embodiment but, on the other hand the appended claims are intended to cover all modifications and alternative constructions within the spirit and scope of the invention.

I claim as my invention:

1. In an article of the character described, a sheet of metal having a laterally extending integral and generally rectangular lug fashioned on one edge thereof, and a second sheet of material having a slot therein receiving said lug with the outer edge portion of said lug projecting beyond the outer surface of said second sheet, said lug having a generally rectangular aperture formed therein separating the central end portion of the lug from the remainder thereof with the outer edge of said aperture paralleling the outer sur face of said second sheet and lying close to but slightly beyond the same, said central end portion of said lug beyond said aperture being distorted in the form of a longitudinal rib projecting laterally out of the plane of the remainder of the lug and substantially at right angles to said second sheet with one end of said rib abutting against the adjacent part of said second sheet to hold it fast against separation from the first named sheet.

2. In an article of the character described a sheet of metal having a laterally extending integral lug fashioned on one edge thereof, and a second sheet of material having a slot therein receiving said lug with the outer edge portion of said lug projecting beyond the outer surface of said second sheet, said lug having an aperture therein separating a part only of the end portion of the lug from the body thereof along a line of cleavage paralleling the outer surface of said second sheet and disposed slightly beyond said surface, a part only of said end portion of said lug being displaced laterally out of the plane of the remainder of said end portion of the lug to overlie the adjacent part of said second sheet and hold it fast against separation from the first named sheet.

3. In an article of the character described a first sheet of metal having a laterally extending lug fashioned on one edge thereof and a second sheet of material having an opening therein receiving said lug with the outer end portion of said lug projecting beyond the outer surface of said second sheet, said lug having an outer end portion separated from the inner part thereof along a line lying substantially in the plane of the top of said second sheet thereby permitting the displacement of said lug end portion out of the plane of the remainder of the lug Without distorting the same, said separated end portion of said lug being distorted in the form of a laterally projecting rib with one end thereof abutting against the adjacent part of said second sheet to hold it fast against separation from the first named sheet.

EDWARD L. BARRETT. 

